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Simple and Robust in vivo and in vitro Approach for Studying Virus Assembly
Published on: March 1, 2012
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Double-stranded RNA virus outer shell assembly by bona fide domain-swapping.
Zhaoyang Sun1, Kamel El Omari1, Xiaoyu Sun2
1Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK.
Nature Communications
|March 14, 2017
Summary
The structure of bacteriophage φ6 reveals how calcium ions regulate outer shell assembly. Protein subunits swap domains, explaining shell formation and providing insights into protein shell evolution.
Area of Science:
- Structural biology
- Virology
- Biochemistry
Background:
- Outer protein shell assembly is crucial for the infectivity of many multi-shelled dsRNA viruses.
- The double-stranded RNA bacteriophage φ6 serves as a prototypic model, with calcium ions promoting its assembly, though biomechanics are unclear.
Purpose of the Study:
- To elucidate the near-atomic resolution structure of the φ6 double-shelled particle.
- To understand the biomechanics of outer shell assembly regulated by calcium ions.
Main Methods:
- Near-atomic resolution structural determination of the φ6 double-shelled particle.
Main Results:
- The outer T=13 shell protein P8 forms trimers with two alpha-helical domains connected by a linker, allowing open and closed conformations.
- In the open conformation, P8 trimers exhibit domain swapping, a key mechanism for shell assembly.
- A mechanistic model for calcium-regulated outer shell assembly was proposed.
Conclusions:
- The study provides a structural basis for calcium-mediated outer shell assembly in bacteriophage φ6.
- It presents a significant example of domain-swapping in a biological context.
- The findings extend domain-swapping theory to closed spherical shells and suggest evolutionary mechanisms for their formation.
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